Territory



(No Model.) A A 2 Sheets-Sheet 1.

D. G. SMITH- ELECTRIC RAILWAY SIGNAL. No. 395,667. Patented Jan. 1 1889.

N. PETERS Fholo-Lilhoguphqr. Ylzuhingion. u c.

(No Model. 2 Sheets-Sheet 2. D. G. SMITH.

. ELECTRIC RAILWAY SIGNAL.

No. 395,667. Patented Jan. 1, 1889.

N. PETERS. PMlflrLMwgnplmr, wasmngion. D. c.

UNITED STATES PATENT OFFI E.

DANIEL G. SMITH, OI POOAT'EIIIJO, IDAlIO TERRITORY, ASSIGNOR TO REINHARTL. BRO\YN, OF SAME PLACE.

ELECTRIC RAlLWAY SlGNAL SPECIFICATION forming part of Letters Patent No.395,667, dated January 1, 1889.

Application filed April 17, 1888. $erial No. 270,944. (No model.)

T 0 mil whom it may (mace/72d:

Be it known that I, DANIEL G. SMITH, of Pocatello, in the county ofBingham and Territory of Idaho, have invented a new and useful,Improvement in Electric Rai lway-Si gnals, (Iii gh1's,) of which the't'ollowin is a specification.

Figure 1 is a plan of a curved section of a railway-track. Fig. 2 is anelevation of a portion of the railway-track and of one wheel of a car orlocomotive with the air-compressing machinery in section. Fig. 3 is avertical section through the operating-lever. Fig. t is an elevation ofa circuit-breaking mechanism, partly in section, and a diagran'i of alocal circuit. Fig. 5 is a section through the shuntmagnet attached toone of the lamps.

The improvements will first be specifically set forth, and at'tm-wardpointed out in the claims.

The mechanism which I employ is as follows:

L represents the main-line circuit, which may extend the whole length ofthe track, or the whole length of the track which it is wished to guard,and through which an electrical current is kept constantly flowing.

b. represents a local circuit connected with the main-line circuit, andhaving therein a series of lamps, I, or magnets for actuating semaphoreor other visible signals, the resistance of said local circuit beinggreater than that of the main circuit. If th. local circuit be appliedto that section of the track illustrated in Fig. 1, it would embraceeither or both ends of said section and carry signals at a u or I) I),or both. 7

At each point where the main-line circuit Ii is connectml with the localcircuit S, I provide a circuit-breaker. (Illustrated in Fig. t.)

f represents a U-shaped vessel, of glass or metal, in which is containeda quantity of mercury, in, on the top of which in one leg of vesselfloats the metallic plate 71 The main-line circuit L is broken at thecircuit-breaker, and its ends pass through an insulatiug-plate in thetop of one leg of the vessel f, and pass downward side by side, butinsulated from each other, to such a dis tance that when the mercury isin a state of.

equilibrium it will press the metallic plate 71 against the ends .9 s ofthe main line, thus completing the circuit.

A represents a reservoir to hold compressed air, placed near thecircuiii-breaker f, and it is connected by the pipe 9 with that end ofthe vessel f through which the wires .9 3 pass. The reservoir A shouldbe provided with a pin-hole, or a slight leak should be left in some ofthe joints, so that when air is compressed within said reservoir it willgradually escape and return to its normal tension.

B represents a lever, pivoted at F in a bracket which is firmly attachedto a bedplate, 11'. Secured on the upper end of the lever l3 is africtioi1-roller, E, which projects within the line of travel of thetread of a carwheel running on rail R, but not far enough to come incontact with the rail when, depressed by the passage of a wheel. In thelower end of the lever B is secured a crossbar, j, having therein holes7t.

and I) represent two single-acting aircompressing cylinders secured tothe bedplate ll, each havi n a piston therein, (marked C and I),) andeach having at its closed end an inlet port provided with aninwardly-opening valve, and an outlet-port provided with an 0utwardly-opei1in valve and connected with the reservoir A by a pipe, c ore.

The piston-rods c c are jointed and each piston-rod passes through ahole, 7a, in crossbarj, and has on its end a nut, 7, by whicharrangement motion of the cross-bar to the left, 'Fi 2, actuatespiston-rod 0 without affecting piston-rod c, and vice versa.

(1 (I are coiled springs within the cylinders 1), sn rrounding thepiston-rods, by which the piston, after bein actuated by the lever B, isforced back to tllGPOSltlOH shown in thedrawings, thereby compressingthe air in. the cyl- 'inder and driving it, through the pipe (2 or e tothe reservoir A.

I represents an incandescentlamp connected in series in the localcircuit S.

To prevent the interruption of the local circuit by the breaking of thelamp, I make a shunt-circuit, p p, which is connected with the n'iagnetlllI of greater resistance than the local circuit S, and one side ofthis shunt-circuit is connected with the pivoted armature N and theother side with the contact-point O.

P represents a spring acting on the lower end of the armature N to holdit away from the core of the magnet, and also aetin g, when its force isovercome and the armature is attracted by the magnet, to hold the otherend of the armature tirmly against the contactpoint 0, thus establishingthe circuit through the line 2) p,- armature N, and contact-point 0.

It is evident that while the current [iows normally through the localcircuit 5 the shuntcircuit will be inoperative, but that an. in.-terruption in the local circuit, as by breaking a lamp, I, causes themagnet M to be energized, attracts armature i and completes theslumt-circuit through contact-point 0, thus simply cutting out thebroken lamp.

The operation of my invention is as follows: The current passing throughthe main-line circuit normally does not attect any ot. the localcircuits. It, now, atrain comes into the section protected by the localcircuit, its wheels \V strike the friction-reller E on lever B andsuccessively depress. the upper end of the lever, thereby, if moving inthe direction indicated by the arrow in Fig. i actuating the piston C incylinder 0, and the recoil of spring (Z, when the lever B rises afterthe passage of the wheel, compresses the air in cylinder C and forces itthrough the pipe 6 into the reservoir A. This is repeated with eachwheel of the train on one side of the track. As soon as the air iscompressed in reservoir A, it tlows through pipe g into one leg ofvessel fand depresses the mercury in that leg, thereby causing themetallic plate 71 to drop away from the terminals 8 s and break theconnection between them, when the current isinunediatel y divertedthrough the local circuit S and. the signals contained therein, andcontinues to How through said local circuit until the gradual escape ofair from the cylinder A permits the mercury to again come to a state ofequilibrium and re-establishes the terminal 3. The length of timerequired for the escape of air from reservoir A should be adjusted byregulating the size of the leak to the length of time that the signalsare to be displayed It is evident that instead 01 using the lamps I forsignals, or in addition to the lamps I, the local circuit S may operatetarget or semaphore signals by means 0t electrically colr trolled.machinery which is well known, and which I therefore do not describe. 7

\Vhat I claim asmy invention, and desire to secure by Letters Patent, is

1. The combination, with a main-line circuit extending between twopoints, a local circuit connected with and of a higher resistance thanthe main circuit, an air-compressor mechanism actuated by a passintrain, and a circuit-breaker operated by air from the air-coinpressormechai'lism to break the main -line circuit, substantially as described.

2. The combination, with a main-line circuit extending between twopoints, a local cir-- cuit connected with and of a higher resistancethan the main circuit, a pivoted lever operated by a passing train, anvair-compressor mechanism, and a eircuit-ln'eaker operated by the airfrom the air-compressor mechanism to break the main-line circuit,substantially as described.

3. The con'ibination, with a main-line circuit extcndin g between twopoints, a local circuit connected with and ot' a higher resistance thanthe main circuit, a lever arranged to be operated by a passing train, anair-compressing cylinder havin a piston connected with the lever, anair-reservoir connected with the cylinder, and a eirmtit-breakeroperated by air from the reservoir to break the main-line circuit,substantially as descrilmd.

4. in combination with. a n'iain-line circuit and a local circuit,including electric signals directly connected therewith and of higherresistance than the main-line circuit, a circuit-breaker consisting of aU-shaped vessel,

f, containing the mercury m, metallic plate 71.,

and insulated terminals 5' 3, connected. with a reservoir for compressedair, adapted to be operated by a passing train, substantially as and forthe purposes set forth.

l).. G. SMITH.

Witnesses:

1-3. W. E. JENNERs,

J. S. CAMPBELL, Jr.

